Choice of ellipses
--- Introduction ---

An ellipse (oriented horizontally/vertically) is described
by an equation of the form

a(x-x0)2 + b(y-y0)2 = c,

or of the form

ax2+ by2+ cx+ dy+ e = 0,

where (x0,y0) is the center of the ellipse and the ratio
between the two axes of the ellipse is described by the ratio between
a and b (how?).

This online exercise can either plot an ellipse and ask you
to recognize its equation among a list to choose from, or give an equation
and ask you to recognize the plotted ellipse among a list to choose from.

Configuration of the exercise :

Style of the exercise:
.

Type of the equation:

Type of variations:
.

And a session will be composed of
questions ( with a score assigned at the end of each session).